Lens grinding machine



Sept. 25, 1934.

Filed Aug. 31, 1932 FIG.5

FIGAL INVENTOR LESKI JOSEPH 5. GA

- ATTORNEY Patented Sept. 25, 1934 This invention relates to abrading machines and more particularly it has reference to machines which are used for grinding and polishing lenses.

*5. One of the objects of my invention is to provide an improved device for grinding and polishing lenses having convex surfaces whose radii of curvature are relatively short. Another object is to provide means for grinding and polishing lenses in which the pressure for urging the lens and lap into contact is applied at or slightly below the surface of the lens. These and other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully described and pointed out in the appended claims.

Referring to the drawing:

Fig. 1 shows my device in operation.

Fig. 2 is a front elevation of my device.

Fig. 3 is a side view' of my device.

Fig. 4: is a top plan view of same.

Fig. 5 is a sectional view illustrating the use of my device.

In the usual practice of grinding and polishing spherical lenses in prescription shops, a single lens blank is attached to a lens block by a suitable adhesive such as pitch. A laphaving the proper curvature is placed on a rotatable spindle and the lens blank is then held firmly down against the rotating lap. A suitable grinding or polishing compound, such as emery or rouge, is, of course, applied to the lap.

In grinding or polishing a spherical convex or plus lens having a curvature with a short radius considerable difilculty is encountered. This is due to the fact that with such a strongly curved convex surface the point of application of the pressure is relatively high above the lens surface. This puts the. lens in a condition of unstable equilibrium so that when pressure is applied there is a great tendency to tip the lens with the result that the lens is often chipped or shattered. Such a tipping of the lens in polishing causes the outer zones of the lens to be completely polished long before the central portion is completely polished.

To overcome these difilculties I have provided a device whereby the effective pressure is applied 50 to the lens block froma plane which is substantially at or below the surface of the strongly curved plus lens. My device, indicated generally at 15, and illustrated on Figs. 1 to 5 of the drawing, comprises a substantially rectangular ring p55 member 16 to which are pivotally mounted, by

. 4 Claims. (01. 51-129) pins thew) depending arms 18 and 18 of the yoke 19. Secured to the yoke 19 is a member 20 r within which a bushing 21 is mounted to turn on the ball bearing 21'. The projection 22 of a lens block 23, carrying lens blank L, is mounted in fill bushing 21 so that the blank may rotate freely. Mounted above and substantially at right angles to yoke 19 is the second yoke 24 having two depending arms 25 which are pivotally connected to ring 16 by pins 26. Mounted on top of yoke .65 24 is a bearing cup member 27 within which the pin 14' on lever 12, pivoted at 13 is adapted to be positioned.

Fig. 1 shows the use of my device in connection with the usual surfacing machine. The pin 14' on lever 12 projects into the bearing cup 27 a and is rigidly secured thereto by set screw 2'7.

It wilLthus be apparent that pressure can be transmitted from the lever 12 through the yoke 24 to the ring member 16 and thence through 15' yoke 19 to the lens block 23. The device 15 is held against rotation though the lens blank L may rotate freely on ball bearing 21'. Pressure is thus applied to the lens block from a plane which is substantially at or slightly below the 30 surface of the lens being operated upon. This afiords greater stability and so reduces the tipping tendency of the lens.

From the foregoing it will be apparent that I am able to attain the objects of my invention and provide an improved device for use in surfacing strongly curved convex lenses. Although I have illustrated my device as applied to a surfacing machine for producing spherical convex lenses, 1 it can be equally well applied to surfacing machines which are used to produce convex toric lenses, as will be understood by those skilled in the art. Various modifications can obviously be made without departing from the spirit of my invention.

I claim: l

1. In a lens grindingand polishing machine the combination of a lap, a member adjacent to the lap and arm extending upwardly from said member, a lens block rotatably mounted on said arm, loo said block carrying a lens to be operated upon and means for applying pressure to said member at a point which lies in a plane below the lens so as to urge said lens and lap into contact with each other. .105

2. In a lens grinding and polishing machine the combination of a ring member, a yoke having two downwardly projecting arms pivotally connected to said ring member, a lens block carried by said yoke, a second yoke positioned above and the pressure is transmitted to said block and the lens urged into contact with the lap.

4. A device of the character described comprising a rotatable spindle carrying a lap, a, lens block carrying a lens to be operated upon, a yoke having two arms pivotally secured to a ring member, a second yoke positioned above said first named yoke, said second yoke having two arms pivotally mounted to said ring member, said lens block being carried by said first named yoke and means for selectively applying pressure to, the; second yoke.

JOSEPH S. GALESKI.

I to;

CERTIFICATE OF CORREGTEON,

Patent No. 1,974,607. September 25, 1934.

JOSEPH S. GALESKI.

it is hereby certified that error appears in the printed speeifieation of the above numbered patent requiring correction as follows: Page 1, line 99, claim 1, strike out the word "and" and insert instead the comma and word an; and that the said Letters Patent should he read with this correction therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 16th day of October, A. D. 1934.

r Leslie Frazer (Seal) Acting Commissioner of Patents. 

